1. Field of the Disclosure
The present disclosure relates to an organic light emitting diode (OLED) display device, and particularly, to an OLED display device and a method of manufacturing the same, which can simplify a manufacturing process and decrease an error.
2. Background of the Disclosure
OLED display devices, which control an amount of light emitted from an organic emission layer to display an image, are attracting much attention as flat panel display devices for reducing weight and volume which are drawbacks of cathode ray tubes (CRTs).
OLED display devices have a structure in which a sub-pixel driver array and an organic emission array are formed on a substrate, and an image is displayed by light emitted from an OLED of the organic emission array. The OLED display devices use a self-emitting element including a thin emission layer formed between electrodes, and thus can be thinned like papers.
The OLED is deteriorated by an internal cause, and for example, an electrode and an emission layer are deteriorated by oxygen, and deterioration is made by a reaction between the emission layer and an interface. Also, the OLED is easily deteriorated by external causes such as external moisture, oxygen, ultraviolet light, and a manufacturing condition of a device. Therefore, packaging of the OLED is important.
In the related art, a method of packaging an OLED uses a method which seals a substrate, on which an OLED is formed, with a protective cap. However, since the method should use a separate material such as an adhesive or a moisture absorbent, the material cost increases. Also, since the protective cap is formed, a volume and a thickness of an OLED display device increase. Also, since a material of the protective cap is glass, it is difficult to realize a flexibility of the OLED display device.
To address such problems, a method which encapsulates an OLED by using a plurality of thin layers is attempted.
FIG. 1 is a schematic cross-sectional view of a related art OLED display device, and FIG. 2 is a flowchart illustrating a process for the related art OLED display device.
Referring to FIGS. 1 and 2, a related art OLED display device 1 includes an OLED 11, which is formed on a substrate 10, and an encapsulating layer which is formed by stacking a plurality of thin layers, namely, a first inorganic layer 12, an organic layer 13, and a second inorganic layer, 14 to cover the OLED 11.
The kind of the substrate 10 is not limited, and for example, the substrate 10 may use a glass substrate, a plastic substrate, or a silicon substrate.
Moreover, each of the first inorganic layer 12 and the second inorganic layer 14 uses one or a combination of two or more of silicon nitride, silicon oxide, metal, and metal oxide.
Moreover, the organic layer 13 uses a polymer, which uses acrylate and an imide-based polymer.
The OLED 11 is formed in a display area of the substrate 10, and although not shown, an organic emission layer (not shown) is formed between a first electrode (not shown) and a second electrode (not shown) in operation S10.
The substrate 10, on which the OLED 11 is formed, is moved a separate chamber (not shown) for an inorganic layer manufacturing process. In operation S20, the first inorganic layer 12 is formed to cover the OLED 11 by performing processes such as chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), thermal deposition, sputtering deposition, ion beam deposition, electron beam deposition, and atomic layer deposition.
Subsequently, the substrate 10 on which the first inorganic layer 12 is formed is moved a separate chamber (not shown) for an organic layer manufacturing process. In operation S30, the organic layer 13 is formed to cover the OLED 11 by performing processes such as screen printing, slot printing, and inkjet.
Subsequently, the substrate 10 on which the inorganic layer 13 is formed is again moved the separate chamber (not shown) for the inorganic layer manufacturing process. In operation S40, the second inorganic layer 14 is formed to cover the organic layer 13 by performing the CVD process or the PECVD process once again, and thus, the OLED 11 is encapsulated.
However, in the above-described process of manufacturing the related art OLED display device, since a process of forming the inorganic layer differs from a process of forming the organic layer, additional process equipment (for example, printing process equipment) is further needed. For this reason, in the related art OLED display device 1, a manufacturing process is complicated, causing an increase in cost.
Furthermore, in a printing process of the organic layer 13, a nozzle is blocked, and an undoped case occurs. For this reason, a foreign material 15 occurs in the organic layer 13. Alternatively, due to a stress characteristic difference between different layers (i.e., the organic layer and the inorganic layer), a layer-crumpled phenomenon or a pinhole occurs at a boundary between the different layers.